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  <div class="section" id="concrete-objects-layer">
<span id="concrete"></span><h1>Concrete Objects Layer<a class="headerlink" href="#concrete-objects-layer" title="Permalink to this headline">¶</a></h1>
<p>The functions in this chapter are specific to certain Python object types.
Passing them an object of the wrong type is not a good idea; if you receive an
object from a Python program and you are not sure that it has the right type,
you must perform a type check first; for example, to check that an object is a
dictionary, use <a title="PyDict_Check" class="reference external" href="dict.html#PyDict_Check"><tt class="xref docutils literal"><span class="pre">PyDict_Check</span></tt></a>.  The chapter is structured like the
&#8220;family tree&#8221; of Python object types.</p>
<div class="admonition warning">
<p class="first admonition-title">Warning</p>
<p class="last">While the functions described in this chapter carefully check the type of the
objects which are passed in, many of them do not check for <em>NULL</em> being passed
instead of a valid object.  Allowing <em>NULL</em> to be passed in can cause memory
access violations and immediate termination of the interpreter.</p>
</div>
<div class="section" id="fundamental-objects">
<span id="fundamental"></span><h2>Fundamental Objects<a class="headerlink" href="#fundamental-objects" title="Permalink to this headline">¶</a></h2>
<p>This section describes Python type objects and the singleton object <tt class="xref docutils literal"><span class="pre">None</span></tt>.</p>
<ul>
<li class="toctree-l1"><a class="reference external" href="type.html">Type Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="none.html">The None Object</a></li>
</ul>
</div>
<div class="section" id="numeric-objects">
<span id="numericobjects"></span><h2>Numeric Objects<a class="headerlink" href="#numeric-objects" title="Permalink to this headline">¶</a></h2>
<ul>
<li class="toctree-l1"><a class="reference external" href="int.html">Plain Integer Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="bool.html">Boolean Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="long.html">Long Integer Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="float.html">Floating Point Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="complex.html">Complex Number Objects</a><ul>
<li class="toctree-l2"><a class="reference external" href="complex.html#complex-numbers-as-c-structures">Complex Numbers as C Structures</a></li>
<li class="toctree-l2"><a class="reference external" href="complex.html#complex-numbers-as-python-objects">Complex Numbers as Python Objects</a></li>
</ul>
</li>
</ul>
</div>
<div class="section" id="sequence-objects">
<span id="sequenceobjects"></span><h2>Sequence Objects<a class="headerlink" href="#sequence-objects" title="Permalink to this headline">¶</a></h2>
<p id="index-10">Generic operations on sequence objects were discussed in the previous chapter;
this section deals with the specific kinds of sequence objects that are
intrinsic to the Python language.</p>
<ul>
<li class="toctree-l1"><a class="reference external" href="bytearray.html">Byte Array Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="string.html">String/Bytes Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="unicode.html">Unicode Objects and Codecs</a><ul>
<li class="toctree-l2"><a class="reference external" href="unicode.html#unicode-objects">Unicode Objects</a></li>
<li class="toctree-l2"><a class="reference external" href="unicode.html#built-in-codecs">Built-in Codecs</a></li>
<li class="toctree-l2"><a class="reference external" href="unicode.html#methods-and-slot-functions">Methods and Slot Functions</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference external" href="buffer.html">Buffer Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="tuple.html">Tuple Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="list.html">List Objects</a></li>
</ul>
</div>
<div class="section" id="mapping-objects">
<span id="mapobjects"></span><h2>Mapping Objects<a class="headerlink" href="#mapping-objects" title="Permalink to this headline">¶</a></h2>
<ul>
<li class="toctree-l1"><a class="reference external" href="dict.html">Dictionary Objects</a></li>
</ul>
</div>
<div class="section" id="other-objects">
<span id="otherobjects"></span><h2>Other Objects<a class="headerlink" href="#other-objects" title="Permalink to this headline">¶</a></h2>
<ul>
<li class="toctree-l1"><a class="reference external" href="class.html">Class and Instance Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="function.html">Function Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="method.html">Method Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="file.html">File Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="module.html">Module Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="iterator.html">Iterator Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="descriptor.html">Descriptor Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="slice.html">Slice Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="weakref.html">Weak Reference Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="cobject.html">CObjects</a></li>
<li class="toctree-l1"><a class="reference external" href="cell.html">Cell Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="gen.html">Generator Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="datetime.html">DateTime Objects</a></li>
<li class="toctree-l1"><a class="reference external" href="set.html">Set Objects</a></li>
</ul>
</div>
</div>


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            <ul>
<li><a class="reference external" href="">Concrete Objects Layer</a><ul>
<li><a class="reference external" href="#fundamental-objects">Fundamental Objects</a><ul>
</ul>
</li>
<li><a class="reference external" href="#numeric-objects">Numeric Objects</a><ul>
</ul>
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<li><a class="reference external" href="#sequence-objects">Sequence Objects</a><ul>
</ul>
</li>
<li><a class="reference external" href="#mapping-objects">Mapping Objects</a><ul>
</ul>
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<li><a class="reference external" href="#other-objects">Other Objects</a><ul>
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